Unmatched quality

The hot springs of Kusatsu are counted among the top three in Japan. They boast powerful anti-bacterial properties said to be able to cure any ailment but lovesickness.
*The three revered hot springs of Japan: Kusatsu Onsen, Gero Onsen, and Arima Onsen

The power to dissolve a nail

Experiments have shown that almost all bacteria and microorganisms in Kusatsu's hot spring waters are unable to proliferate and soon die. This strong acidity (pH 1.6 - 2.1) is the secret to Kusatsu Onsen's sterilizing powers. A six-inch nail left in the hot spring will dissolve without a trace in around 10 days.


The power to create art

The hot spring waters of Kusatsu can also be used to make your own original nameplate by embossing letters or characters onto stone. The process involves painting your name onto limestone and then leaving it in the hot spring for around two weeks. The unpainted parts of the rock will dissolve to produce a fine looking embossed carving. Why not try your hand at making a one-of-a-kind souvenir as a reminder of your trip to Kusatsu Onsen?
For more information about this experience, please contact the Shinagi Dam Water Quality Management Office.


Like a good doctor

Kusatsu's hot springs have a sterilizing effect as a result of the extremely strong acidity (pH 1.6 - 2.1) of the water. E. coli and other bacteria cannot survive for even one minute. We therefore know that hot springs are effective in treating afflictions caused by bacteria, as well as inflammation. The members of Kusatsu's very own soccer team, THESPA Kusatsu Challengers, also head straight to the hot springs after a game to disinfect their grazes and soothe their tired bodies.


Spring qualities / Therapeutic benefits

Spring qualities Acidic spring water containing sulfur, aluminum sulfate, and chloride (Yubatake source)
Therapeutic benefits Neuralgia, muscular pain, joint pain, chronic skin ailments, stiff shoulders, bruises, sprains, convalescence, recuperation, promotion of general health, chronic women's diseases, diabetes, high blood pressure, and hardening of the arteries